Background: To investigate whether surface microdialysis (μD) sampling in probes covered by a plastic film, as compared to noncovered and to intraparenchymatous probes, would increase the technique's sensitivity for pathophysiologic events occurring in a liver ischemia-reperfusion model. Placement of μD probes in the parenchyma of an organ, as is conventionally done, may cause adverse effects, e.g., bleeding, possibly influencing outcome.

Methods: A transient ischemia-reperfusion model of the liver was used in six anesthetized normoventilated pigs. μD probes were placed in the parenchyma and on the liver surface. Surface probes were either left uncovered or were covered by plastic film.

Results: Lactate and glucose levels were significantly higher in plastic film covered probes than in uncovered surface probes throughout the ischemic period. Glycerol levels were significantly higher in plastic film covered probes than in uncovered surface probes at 30 and 45 min into ischemia.

Conclusions: Covering the μD probe increases the sensibility of the μD–technique in monitoring an ischemic insult and reperfusion in the liver. These findings confirm that the principle of surface μD works, possibly replacing need of intraparenchymatous placement of μD probes. Surface μD seemingly allows, noninvasively from an organ's surface, via the extracellular compartment, assessment of intracellular metabolic events. The finding that covered surface μD probes allows detection of local metabolic changes earlier than do intraparenchymatous probes, merit further investigation focusing on μD probe design.

Microdialysis (MD) can be used to study metabolism of the beating heart. We investigated whether microdialysis results obtained from epicardial (surface) sampling reflect acute changes in the same way as myocardial sampling from within the substance of the ventricular wall. In anaesthetized open-thorax pigs a coronary snare was placed. One microdialysis probe was placed with the sampling membrane intramyocardially (myocardial), and a second probe was placed with the sampling membrane epicardially (surface), both in the area which was made ischaemic. Ten minutes collection intervals were used for microdialysis samples. Samples from 19 pigs were analysed for lactate, glucose, pyruvate and glycerol during equilibration, baseline, ischaemia and reperfusion periods. For both probes (surface and myocardial), a total of 475 paired simultaneous samples were analysed. Results from analyses showed no differences in relative changes for glucose, lactate and glycerol during baseline, ischaemia and reperfusion. Surface microdialysis sampling is a new application of the microdialysis technique that shows promise and should be further studied.

Mammal metabolism is intimately connected to the maintenance of body temperature. While metabolic pathways invariably produce heat as a by-product, the natural heat present in the environment also plays a role in defining the adaptive metabolism and general physiology of an organism. This thesis aims to discuss basic aspects of energy expenditure and their interactions with energy stores and body composition. In Paper I, we apply a new technique – high-resolution laser-Doppler imaging – to describe physiological regulatory features of adrenergically-stimulated blood flow in brown adipose tissue, and evaluate the validity of blood flow as a parameter to estimate nonshivering thermogenesis. Paper II focuses on the central regulation of body temperature. In the absence of bombesin receptor subtype-3, mice present an altered neurological body temperature setpoint, while peripheral thermogenic capacity remains intact. We conclude that brown adipose tissue malfunction is not the cause of the hypothermia observed in this mouse model. Paper III incorporates measurements of body temperature to the energy expenditure of different sources: basal metabolic rate, physical activity, thermic effect of food, and cold-induced thermogenesis. We describe basic aspects of dynamic insulation, energetic costs of circadian variation and hypothesize that physical activity may change the body temperature setpoint. Paper IV describes methodological issues related to glucose tolerance tests in obese mice. We conclude that the erroneous scaling of doses may affect the interpretation of metabolic health in mouse models, and suggest a new methodology. Paper V describes the outcomes caused by the expression of the human Cidea protein in adipose tissue of mice and suggests that this protein may clarify the link between adipose tissue expansion and healthy obesity. Paper VI explores the dissociation between thiazolidinedione-induced adipose tissue “browning” and reduced blood glycaemia. We demonstrate that although this pharmacological class tends to induce some level of brown adipose tissue recruitment, this phenomenon does not define its antidiabetic effects.

To develop novel strategies for prevention and treatment of dyslipidemia, it is essential to understand the pathophysiology of dyslipoproteinemia in humans. Lipoprotein metabolism is a complex system in which abnormal concentrations of various lipoprotein particles can result from alterations in their rates of production, conversion, and/or catabolism. Traditional methods that measure plasma lipoprotein concentrations only provide static estimates of lipoprotein metabolism and hence limited mechanistic information. By contrast, the use of tracers labeled with stable isotopes and mathematical modeling, provides us with a powerful tool for probing lipid and lipoprotein kinetics in vivo and furthering our understanding of the pathogenesis of dyslipoproteinemia.

Purpose: In healthy individuals, high carbohydrate intake is recommended during prolonged exercise for maximum performance. In type 1 diabetes (T1D), this would alter the insulin requirements. The aim of the study was to evaluate the safety of high glucose supplementation during prolonged exercise and the glucose control when a novel strategy of increased carbohydrate supply was implemented during prolonged exercise in T1D.

Methods: Eight subjects with T1D participated in a sports camp including sessions of prolonged exercise and individualized feedback during three consecutive days. This was later followed by a 90 km cross-country skiing race. Large amounts of carbohydrates, 75 g/h, were supplied during exercise and the insulin requirements were registered. Glucose was measured before, during and after exercise aiming at euglycaemia, 4-8 mmol/L (72-144 mg/dL). During the race, continuous glucose monitoring (CGM) was used as an aspect of safety and to allow direct and individual adjustments.

Conclusion: In this study, large carbohydrate supplementation in T1D individuals during prolonged aerobic exercise is safe and allows the subjects to maintain glycaemic control and indicates the feasibility of CGM under these conditions.

Aortic stenosis is the most common valvular disease in the adult population. A significant aortic stenosis is a serious condition, and if a symptomatic patient is not operated on, it may in most cases cause death. We have examined how many aortic stenoses that were diagnosed during one year, and a follow-up of the patients was also performed. We found 77 patients with significant aortic stenosis with a mean age of 76±13 years. At the time of follow-up 30 (39%) patients, aged between 29-85 years, had been surgically treated with implantation of a valve prosthesis within 2-23 months after the initial examination. At this initial examination 14 of the 30 patients who later underwent surgery had no symptoms. A coronary bypass operation was also performed on seven patients. Postoperative complications were observed in six patients, but none of them was fatal. At the initial examinations there were 26 (34%) patients with a significant aortic stenosis and symptoms who were not treated surgically. The main reason why these patients were not operated was high age, unwillingness, or severe left ventricular dysfunction. This study indicates the importance of repeated clinical and echocardiograpic examinations in patients with aortic stenosis. Almost half of the patients, that later underwent surgery, had no symptoms at the initial examination, but later developed symptoms which made surgery necessary. In one third of the patients no surgery was performed in spite of clinical symptoms.

The aim of this thesis was to investigate roller ski characteristics; classical and freestyle roller skis’ rolling resistance coefficients (μR) and classical style roller skis’ static friction coefficients (μS), and to study the influence of different μR and μS on cross-country skiers’ performance and both physiological and biomechanical indices. The aim was also to study differences in skiing economy and efficiency between recreational skiers, female and male junior and senior elite cross-country skiers.The experiments showed that during a time period of 30 minutes of rolling on a treadmill (warm-up), μR decreased significantly (p<0.05) to about 60-65 % and 70-75 % of its initial value for freestyle and classical roller skis respectively. Also, there was a significant influence of normal force on μR, while different velocities and inclinations of the treadmill only resulted in small changes in μR.The study of the influence on physiological variables of a ~50 % change in μR showed that during submaximal steady rate exercise, external power, oxygen uptake, heart rate and blood lactate were significantly changed, while there were non-significant or only small changes to cycle rate, cycle length and ratings of perceived exertion. Incremental maximal tests showed that time to exhaustion was significantly changed and this occurred without a change in maximal power, maximal oxygen uptake, maximal heart rate and blood lactate, and that the influence on ratings of perceived exertion was non-significant or small.The study of classical style roller skis μS showed values that were five to eight times more than the values of μS reported from on-snow skiing with grip-waxed cross-country skis.The subsequent physiological and biomechanical experiments with different μS showed a significantly lower skiing economy (~14 % higher v̇O2), higher heart rate, lower propulsive forces coming from the legs and shorter time to exhaustion (~30 %) when using a different type of roller ski with a μS similar to on-snow skiing, while there was no difference between tests when using different pairs of roller skis with a (similar) higher μS.The part of the thesis which focused on skiing economy and efficiency as a function of skill, age and gender, showed that the elite cross-country skiers had better skiing economy and higher gross efficiency (5-18 %) compared with the recreational skiers, and the senior elite had better economy and higher efficiency (4-5 %) than their junior counterparts, while no differences could be found between the genders.

Modern ski-treadmills allow cross-country skiers, biathletes and ski-orienteers to test their physical fitness in a laboratory environment whilst performing classical and freestyle (skating) techniques on roller skis. For elite athletes the differences in performance between test occasions are quite small, thus emphasising the importance of knowing the roller skis’ rolling resistance in order to allow the correct comparison between the results of different test occasions. In this study the roller skis’ rolling resistance has been measured using equipment on the ski-treadmill. The study investigates the influence of significant changes in rolling resistance on physiological variables. The results show that during submaximal exercise, heart rate, blood lactate, power and oxygen uptake are significantly changed by different rolling resistances, while there are no significant or only small changes to cycle rate, cycle length and ratings of perceived exertion. Incremental maximal tests show that time to exhaustion is significantly changed by different rolling resistances and this occurred without significant changes in maximal oxygen uptake and heart rate, and the influence on maximal power and ratings of perceived exertion were insignificant or small.

Modern ski-treadmills allow cross-country skiers, biathletes and ski-orienteers to test their physical fitness in a laboratory environment whilst performing classical and freestyle (skating) techniques on roller skis. For elite athletes, the differences in performance between test occasions are quite small, thus emphasising the importance of knowing the roller skis’ rolling resistance in order to allow the correct comparison between the results of different test occasions. In this study, the roller skis’ rolling resistance was measured on the ski-treadmill’s surface using a roller ski rolling resistance measurement system specially produced for this purpose. The study investigated the influence of significant changes in rolling resistance on physiological variables. The results showed that during submaximal exercise, power, oxygen uptake, heart rate and blood lactate were significantly changed by different rolling resistances, while there were no significant or only small changes to cycle rate, cycle length and ratings of perceived exertion. Incremental maximal tests showed that time to exhaustion was significantly changed by different rolling resistances and this occurred without significant changes in maximal power, maximal oxygen uptake, maximal heart rate and blood lactate, and that the influence on ratings of perceived exertion were insignificant or small.

Modern treadmills allow cross-country skiers, biathletes and ski-orienteers to test their physical performance under laboratory conditions using classical and freestyle techniques on roller skis. The differences in performance between tests are quite small for elite athletes, and it is therefore of great importance to control the rolling resistance of the roller skis. Otherwise different physiological tests cannot be accurately compared.

This study shows that during a warm-up period of 30 minutes the coefficient of rolling resistance (µR) decreases to about 60-65% and 70-75% of its initial value for freestyle and classical roller skis respectively.

Simultaneous measurements of temperature and µR shows that stabilized rolling resistance corresponds to a certain running temperature for a given normal force on the roller ski.

Tests were also performed on the influence on µR of normal force, velocity and inclination. Normal forces produced significant influence on µR , while different velocities and inclinations of the treadmill only resulted in small changes in µR.

The purpose of this study was to investigate the influence of classical style roller skis' grip (static friction coefficients, μ S) on cross-country skiers' oxygen consumption and leg forces during treadmill roller skiing, when using the diagonal stride and kick double poling techniques. The study used ratcheted wheel roller skis from the open market and a uniquely designed roller ski with an adjustable camber and grip function. The results showed significantly (P≤0.05) higher oxygen consumption (∼14%), heart rate (∼7%), and lower propulsive forces from the legs during submaximal exercise and a shorter time to exhaustion (∼30%) in incremental maximal tests when using roller skis with a μ S similar to on-snow skiing, while there was no difference between tests when using different pairs of roller skis with a similar, higher μ S. Thus, we concluded that oxygen consumption (skiing economy), propulsive leg forces, and performance time are highly changed for the worse when using roller skis with a lower μ S, such as for on-snow skiing with grip-waxed cross-country skis, in comparison to ratcheted wheel roller skis with several times higher μ S.

Cross-country skiers use roller skis for their snow-free training with the aim of imitating skiing on snow. Also, exercise laboratories evaluate the biomechanics and physiology of cross-country skiing using roller skis on a treadmill. The roller skis on the market that are constructed for use in the classical style are equipped with a front and a back wheel, one of which has a ratchet to enable it to grip the surface when diagonal striding and kick double poling (static friction). The aim of this study was to investigate static friction coefficients (μS) of ratcheted wheel roller skis, and compare the results to the μS reported from skiing on snow with grip-waxed cross-country skis. Also, a new type of roller ski with a camber and adjustable grip function was evaluated. The results showed that ratcheted wheel roller skis, on a treadmill rubber mat and on dry and wet asphalt surfaces, reached μS values that were five to eight times greater than the values reported from on-snow skiing with grip-waxed cross-country skis. For the roller skis with a camber and adjustable grip function, the μs could be varied from no grip at all up to the level of the tested ratcheted wheel roller skis.

The purpose of this study was to investigate and compare skiing economy and gross efficiency in cross-country skiers of different performance levels, ages and genders; male recreational skiers and elite senior and junior cross-country skiers of both genders. The skiers performed tests involving roller skiing on a treadmill using the gear 3 and diagonal stride techniques. The elite crosscountry skiers were found to have better skiing economy and higher gross efficiency (5-18%) compared with the recreational skiers (p < 0.05) and the senior elite had better economy and higher efficiency (4-5%) than their junior counterparts (p < 0.05), whereas no differences could be found between the genders. Also, large ranges in economy and gross efficiency were found in all groups. It was concluded that, in addition to v̇O2peak, skiing economy and gross efficiency have a great influence on the differences in performance times between recreational and junior and senior elite cross-country skiers, as well as between individual skiers within the different categories. Thus, we recommend crosscountry skiers at all performance levels to test not only v̇O2peak, but also skiing economy and efficiency.

In mammals, gene transcription is a step subjected to tight regulation mechanisms. In fact, changes in mRNA levels in the central nervous system (CNS) can account for numerous phenotypic differences in brain function. We performed a high-resolution analysis of mRNA expression levels for 37 genes selected from a normal rat hippocampus cDNA library. mRNA amounts were quantified using a Real Time PCR SYBR Green assay. We found that, in general, individuals from an inbred rat population (n = 20) have shown 2-3 times differences in the basal level of expression of the genes analyzed. Up to several fold differences among individuals were observed for certain genes. These inter-individual differences were obtained after correction for the different amounts of mRNA in each sample. Power calculations were performed to determine the number of individuals required to detect reliable differences in expression levels between a control and an experimental group. These data indicated that, depending on the variability of the candidate gene selected, it was necessary to analyze from five to 135 individuals in each group to detect differences of 50% in the levels of mRNA expression between two groups investigated. The comparison of mRNA abundance from different genes revealed a wide range of expression levels for the 37 genes, showing a 26,000-fold difference between the highest and lowest expressed gene.

BACKGROUND: Children with recurrent pain of negative chronic stress origin from different locations have a characteristic pattern of tender points in the temporal, trapezoid, great pectoral and abdominal muscles. We tested the hypothesis that the startle reaction is activated in these children and that some of the startle-activated muscles are related to the tender point pattern and the recurrent pain.

METHODS: In children/adolescents, aged 10-17 years, 19 with recurrent psychosomatic pain (PAIN) and 23 controls (CON) we measured and analysed resting activity and acoustic startle response with electromyography (EMG) for the muscles involved in the pattern of tender points and also the lumbar erector spinae.

RESULTS: The PAIN group showed higher resting activity and higher acoustic startle response values than the CON group for all six muscles together regarding the mean amplitude in the initial 200 ms, and during the burst of activity, and longer burst duration and shorter burst latency. For PAIN versus CON, all separate muscles showed generally higher values of EMG amplitudes and burst durations, and shorter latencies for the burst onset in all measures; with significance or strong trends for several parameters and muscles.

CONCLUSION: For the first time in children with recurrent psychosomatic pain, increased resting activity and potentiated startle response were demonstrated in the muscles involved in the stress tender point pattern.

SIGNIFICANCE: This study demonstrates in adolescents how recurrent pain of negative stress origin from the head, stomach, back and chest is related to increased startle reaction and increased muscular tension in these regions. This study contributes to the understanding of the mechanisms underlying the global burden of recurrent pain.

Explosive rotational movements are parts of many sports such as golf, tennis and baseball. Rotational strength and power tests exist, but valid and reliable tests to measure standing rotational strength and standing rotational power are lacking. 1080 Quantum is a machine wich can measure, speed, force and power and has several different resistance modes was used for testing rotational power and strength in this study. Aim: The aim was to investigate the validity and reliability of two new standing Quantum rotational tests; one measuring maximal rotational strength (1RM) and one measuring rotational power. Methods: Fifteen subjects, 8 men and 7 women, with at least one year of experience of resistance training participated in the study. The two new tests were: the Quantum power rotational test (PRT) and the Quantum 1RM rotational test (1RMRT). Testing occured during two sessions and during the first session construct validity of the two new rotational tests was assessed with a standing medicine ball throw (MB) and a sitting rotational power test (SRT). During the second session PRT and 1RMRT were tested for test-retest reliability. To study construct validity á priori hypothesis were stated and data were analyzed with Spearman´s correlation coefficent (rs). Intra correaltion coefficient (ICC) was used for test-retest reliability for PRT and 1RMRT. Results: Priori hypotheses were all fullfilled. Correlations found were considered good between PRT and MB (rs=0.80), moderate between PRT and SRT (rs=0.52), excellent between 1RMRT and MB (rs=0.90), moderate between 1RMRT and SRT (rs=0.73) and good between PRT and 1RMRT (rs=0.81). Excellent test-retest reliability was found for PRT (ICC=0.94, 95% CI (0.80-0.99)) and 1RMRT (ICC=0.98, 95% CI (0.92-0.99)) Conclusion: The two new rotational tests performed in 1080 Quantum both assessed construct validity and test-retest reliability. PRT can be used to measure standing rotational power and 1RMRT can be used to measure standing rotational maximum strength.

Skeletal muscle atrophy and strength loss induced by short-term simulated spaceflight are offset or attenuated by resistance exercise (RE). This study compared the effects of plantar flexor and knee extensor RE on muscle size and function in 17 healthy men (aged 26–41years) subjected to 90 days 6 head-down-tilt bed rest with (BRE; n=8) or without (BR; n=9) RE. The RE program consisted of coupled maximal concentric and eccentric actions in the supine squat (4 sets of 7 repetitions) and calf press (4·14) every third day employing a gravity-independent flywheel ergometer (FW). Prior to, and following bed rest, muscle volume was assessed using magnetic resonance imaging. Similarly, muscle strength and power and surface lectromyographic (EMG) activity were determined during maximal actions using FW or isokinetic dynamometry. In BR, knee extensor and plantar flexor muscle volume decreased (P<0.05) 18% and 29%, respectively. Torque or force and power decreased (P<0.05) 31–60% (knee extension) and 37–56% (plantar flexion) while knee extensor and plantar flexor EMG activity decreased 31–38% and 28–35%, respectively following BR. Muscle atrophy in BRE was prevented (P>0.05; knee extensors) or attenuated ()15%; plantar flexors). BRE maintained task-specific force, power and EMG activity. The decrease in non-task-specific torque was less (P<0.05) than in BR. The present data imply that the triceps surae and quadriceps muscles show different responsiveness to long-term bed rest with or without resistance exercise. The results also suggest that designing in-flight resistance exercise protocols for space travellers is complex and must extend beyond preserving

This study determined changes in knee extensor and plantar flexor muscle volume during 29 days of bed rest with or without resistance exercise using a gravity-independent flywheel ergometer. METHODS: Seventeen men (26-41 years) were subjected to 29 days of bed rest with (n = 8) or without (n = 9) resistance exercise; Supine Squat (SS) and Calf Press (CP) performed every third day. Quadriceps and triceps surae muscle volume was determined before and after bed rest and force and power were measured during training. Prior to these interventions, reproducibility of this device for training and testing was assessed in 23 subjects who performed bilateral maximal concentric, eccentric and isometric (MVC) knee extensions and plantar flexions over repeated sessions with simultaneous measurements of force, power and electromyographic (EMG) activity. RESULTS: Quadriceps and triceps surae muscle volume decreased (P < 0.05) 10 and 16%, respectively, after 29 days bed rest. Exercise maintained quadriceps volume and mitigated triceps surae atrophy. Thus, either muscle showed different response across subject groups (P < 0.05). Force and power output during training were either maintained (P > 0.05) or increased (P < 0.05). EMG amplitude in the training mode was similar (SS; P > 0.05) or greater (CP; P < 0.05) compared with that elicited during MVC. Peak force and power test-retest coefficient of variation (CV) ranged 5-6% and 7-8% for SS and CP, respectively. CONCLUSION: The present data suggest that this resistance exercise paradigm counteracts quadriceps and abates the more substantial triceps surae muscle atrophy in bedridden subjects, and therefore should be an important asset to space travellers.

During mechanical ventilation, patients are connected to the ventilator by an endotracheal tube. The tube needs to be cleaned from mucus by suction, which can cause negative effects such as lung collapse, hypoxemia and desaturation. These can be avoided by preoxygenation, change of ventilator settings, use of closed suction systems and recruitment manoeuvres. The aim of the study was to investigate the effects of endotracheal suction during different ventilator settings and by different suction methods. A method to reverse side effects was investigated.

In anaesthetized pigs, the effect of suction during volume and pressure-controlled ventilation was investigated, and the effect of different suction systems and catheter sizes were compared. Suction efficacy was investigated in a bench study. The effect of recruitment manoeuvre added after suction, i.e. post-suction recruitment manoeuvre was evaluated.

Endotracheal suction causes lung volume loss leading to impaired gas exchange, an effect that is more severe in pressure-controlled ventilation than in volume-controlled ventilation. When 14 French suction catheters were used more side effects were found compared to 12 French catheters, but no difference was found between open and closed suction system in pressure-controlled ventilation. Open suction system was more effective to remove mucus compared to closed system. Post-suction recruitment manoeuvre restored the side effects after the first recruitment when it was applied directly after suction.

In conclusion, open endotracheal suction causes impairment in gas exchange and lung mechanics, and more so in pressure-controlled than in volume-controlled mode. These changes can be minimized if smaller suction catheters are used. A post-suction recruitment manoeuvre applied directly after suction restores lung function. It is obvious that the recruitment manoeuvre should be added directly after suction, because if the manoeuvre is delayed and the lung is collapsed and left collapsed, it will be more difficult to recruit the lung.

To investigate the effects of endotracheal suction in volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) with an open suction system (OSS) or a closed suction system (CSS).

DESIGN:

Randomized comparison.

SETTING:

Animal research laboratory.

PATIENTS:

Twelve healthy anesthetized pigs.

INTERVENTIONS:

The effects of endotracheal suction during VCV and PCV with tidal volume (VT) of 14 mL/kg were compared. A 60-mm inner-diameter endotracheal tube was used. Ten-second suction was performed using OSS and CSS with 12F and 14F catheters connected to - 14 kPa vacuum.

Endotracheal suction can cause partial lung collapse and hypoxia and alter lung mechanics. We investigated the effects of adding a recruitment manoeuvre directly after endotracheal suction to restore lung volume in volume-controlled ventilation and pressure-controlled ventilation modes. Five anaesthetized pigs were investigated. The effects of endotracheal suction with or without a recruitment manoeuvre were compared in random order. In volume-controlled ventilation, compliance decreased after suction from 33 +/- 5 to 26 +/- 6 ml x cmH2O(-1) (P<0.05), and 30 minutes later it remained decreased at 25 +/- 6 ml x cmH2O(-1). Venous admixture increased after suction from 5 +/- 2 to 8 +/- 4% (P<0.05), but had recovered at 30 minutes. In pressure-controlled ventilation, compliance decreased after suction from 34 +/- 3 to 25 +/- 7 ml x cmH2O(-1) (P<0.05), and 30 minutes later it remained decreased at 25 +/- 7 ml x cmH2O(-1). Venous admixture increased after suction from 5 +/- 2 to 13 +/- 7% (P<0.05), and had not recovered after 30 minutes, 10 +/- 4%. When a recruitment manoeuvre was applied directly after suction, no negative side-effects were registered in volume-controlled ventilation or pressure-controlled ventilation. We conclude that the impairment of lung mechanics and gas exchange induced by endotracheal suction can be prevented by a simple post-suction recruitment manoeuvre. Further studies are needed to identify a suitable suction recruitment manoeuvre in patients with diseased lungs.

Background: The single nucleotide polymorphism (SNP) LCT -13910 C>T, associated with genetically determined phenotypes of lactase persistence (LP) or non-persistence (LNP), was studied in relation to the metabolic syndrome (MS).

AIim of the study: The aim was to determine if milk intake and MS are associated. We applied Mendelian randomization (MR). The SNP, LCT -13910 C>T, with the genotypes LP (TT/CT) and LNP (CC), was taken as a proxy for milk consumption.

The lateral reticular nucleus (LRN) is a major precerebellar centre of mossy fibre information to the cerebellum from the spinal cord that is distinct from the direct spinocerebellar paths. The LRN has traditionally been considered to provide the cerebellum with segregated information from several spinal systems controlling posture, reaching, grasping, locomotion, scratching and respiration. However, results are presented that show extensive convergence on a majority of LRN neurons from spinal systems. We propose a new hypothesis suggesting that the LRN may use extensive convergence from the different input systems to provide overview and integration of linked motor components to the cerebellum. This integrated information is sent in parallel with the segregated information from the individual systems to the cerebellum that finally may compare the activity and make necessary adjustments of various motor behaviours.

The literature on premotoneuronal and direct corticomotoneuronal (CM) control in the cat and macaque monkey is reviewed. The available experimental findings are not in accordance with a recently proposed hypothesis that direct CM connections have "replaced" the premotoneuronal pathways. Instead, we propose that premotoneuronal CM control plays an important role in motor control also in primates and that the direct CM connection has been added during phylogeny.

In motor control, the general view is still that spinal interneurons mainly contribute to reflexes and automatic movements. The question raised here is whether spinal interneurons can mediate the cortical command for independent finger movements, like a precision grip between the thumb and index finger in the macaque monkey, or if this function depends exclusively on a direct corticomotoneuronal pathway. This study is a followup of a previous report (Sasaki et al. J Neurophysiol 92: 3142-3147, 2004) in which we trained macaque monkeys to pick a small piece of sweet potato from a cylinder by a precision grip between the index finger and thumb. We have now isolated one spinal interneuronal system, the C3-C4 propriospinal interneurons with projection to hand and arm motoneurons. In the previous study, the lateral corticospinal tract (CST) was interrupted in C4/C5 (input intact to the C3-C4 propriospinal interneurons), and in this study, the CST was interrupted in C2 (input abolished). The precision grip could be performed within the first 15 days after a CST lesion in C4/C5 but not in C2. We conclude that C3-C4 propriospinal interneurons also can carry the command for precision grip.

Estrogens exert a substantial influence on the transmission of nociceptive stimuli and the susceptibility to pain disorders as made evident by studies in both animals and human subjects. The estrogen receptor (ER) seems to be of crucial importance to the cellular mechanisms underlying such an influence. However, it has not been clarified whether nociceptive neurons activated by pain express ERs. In this study, a noxious injection of formalin was given into the lower lip of female rats, thereby activating nociceptive neurons in the trigeminal subnucleus caudalis as demonstrated by immunohistochemical labeling of Fos. Using a dual-label immunohistochemistry protocol ERalpha-containing cells were visualized in the same sections. In the superficial layers of the medullary dorsal horn, 12% of ERalpha-labeled cells, mainly located in lamina II, also expressed noxious-induced Fos. These findings show that nociceptive-responsive neurons in the medullary dorsal horn express ERalpha, thus providing a possible morphological basis for the hypothesis that estrogens directly regulate pain transmission at this level.

Using an immunohistochemical technique, we demonstrate that large numbers of neurons in the laminar spinal trigeminal nucleus and spinal gray matter of the female rat express estrogen receptors (ER). Densely packed ER-immunoreactive neurons were present in lamina II, but labeled neurons were also present in lamina I, the neck of the dorsal horn, and in lamina X. Labeling was present throughout the length of the spinal cord, with the exception of segments caudal to S1, which were unlabeled. The distribution of ER-containing neurons to areas that are involved in processing of primary afferent nociceptive information suggests that the pain modulatory effects of estrogen may be exerted at the spinal level.

Skeletal muscle is a dynamic tissue with a remarkable ability to continuously respond to environmental stimuli. Among its adaptive responses is the widely investigated ability of skeletal muscle to regenerate after loading or injury or both. Although significant basic science efforts have been dedicated to better understand the underlying mechanism controlling skeletal muscle regeneration, there has been relatively little impact in the clinical approaches used to treat skeletal muscle injuries and wasting. The purpose of this review article is to provide an overview of the basic biology of satellite cell function in response to muscle loading and to relate these findings in the context of aging and neuromuscular pathology for the rehabilitation medicine specialist.

The present study evaluated the effect of a sleep high-train low regimen on the finger cold-induced vasodilation (CIVD) response. Seventeen healthy males were assigned to either a control (CON; n=9) or experimental (EXP; n=8) group. Each group participated in a 28-day aerobic training program of daily 1-h exercise (50% of peak power output). During the training period, the EXP group slept at a simulated altitude of 2800 meters (week 1) to 3400 m (week 4) above sea level. Normoxic (CIVD(NOR); CON and EXP groups) and hypoxic (CIVD(HYPO); F(I)O(2)=0.12; EXP group only) CIVD characteristics were assessed before and after the training period during a 30-min immersion of the hand in 8°C water. After the intervention, the EXP group had increased average finger skin temperature (CIVD(NOR): +0.5°C; CIVD(HYPO): +0.5°C), number of waves (CIVD(NOR): +0.5; CIVD(HYPO): +0.6), and CIVD amplitude (CIVD(NOR): +1.5°C; CIVD(HYPO): +3°C) in both CIVD tests (p<0.05). In contrast, the CON group had an increase in only the CIVD amplitude (+0.5°C; p<0.05). Thus, the enhancement of aerobic performance combined with altitude acclimatization achieved with the sleep high-train low regimen contributed to an improved finger CIVD response during cold-water hand immersion in both normoxic and hypoxic conditions.

RESULTS: There was a significant increase in P-tau in the SIM-group during follow-up, while P-tau in MIM and NIM did not change. Eighty-three percent of the SIM-patients converted to dementia (80% AD), while most MIM- and NIM-patients remained non-demented. T-tau- and Abeta42-levels did not change in any of the memory groups during follow-up.

CONCLUSION: Increasing P-tau levels during cognitive decline and conversion to dementia suggest that P-tau may be useful as a longitudinal marker of the neurodegenerative process.

The overall aim of this thesis was to study the myouelectric activity of all major muscles involved in the movements and stabilization of the trunk, pelvis and hips during training exercises, postures, motor tasks, maximal strength performance and locomotion. By use of ultra-sound, EMG electrodes could be guided safely and accurately into muscles situated even close to the spinal column, such as psoas, quadratus lumborum and deep parts of erector spinae.

A task specific variation in activation levels were seen between muscle synergies, as well as between individual muscles within a synergy. Selective engagement of the abdominal muscles could be achieved in trunk flexion sit-ups, that is lifting only the upper trunk from the floor. An even higher activation of abdominal muscles was needed for static stabilization of the trunk and pelvis during hip flexion sit-ups, whereas single leg lifts were performed without involvement of the abdominal muscles. A selective activation of either the iliacus or psoas muscle was observed, for example in certain types of training exercises and in walking and running. Applying bending moments to the spine, resulted in a grading of the muscle activation response according to mechanical advantage, that is highest in the quadratus lumborum in lateral loading and in the superficial erector spinae in ventral loading. An exception was the most forward flexed position in standing where the superficial erector spinae "relaxed" but quadratus lumborum remained active. In general, the level of EMG in maximal efforts was maintained at the same high level irrespective of position in the range of motion, despite a marked variation in strength output. This position-dependency, as well as the strength values as such, varied in a specific way in groups of athletes, related to previous background.

These data contribute to the understanding of muscle function and motor control of the trunk , pelvis and hips. They are also of relevance when evaluating and designing tests and training programs in rehabilitation and sport contexts as well as for improving biomechanical models of spinal loading.

It has been scientifically demonstrated that there are blood vessels with pathologically high blood flow inside and outside the ventral part of the Achilles tendon in chronic painful tendinosis, but not in pain-free normal Achilles tendons. Injections of local anaesthesia on the outside of the ventral part of the tendon have been found to temporarily abolish the tendon pain, and this has been an inspiration in the development of a new approach in the treatment of tendinosis: Based on ultrasound- (US) and colour Doppler- (CD) guidance, the sclerosing substance polidocanol, for many years used in treatment of varicose veins, was injected targeting the area of high-flow blood vessels just outside the ventral part of the Achilles tendon. The treatment has in pilot studies and a randomized controlled clinical study been shown to cure the pain in about 70-80 % of the patients. Also, follow up examinations, using US and CD, have shown a possible remodeling potential of the tendon. There is some previous information available on the innervation patterns of the human Achilles tendon itself. However, the innervation patterns of the area just outside the ventral part of the tendon, i.e. the area that is targeted by the sclerosing injections (target area), are unknown. This includes a lack of information concerning the nerve-related characteristics of the blood vessels in the area. In this study, therefore, tissue specimens from this target area, obtained during surgical treatment of patients with chronic painful mid-portion Achilles tendinosis, were examined. Histological and immunohistochemical examinations were performed. In the tissue of the target area, in which loose connective tissue and fat cells were frequent constituents, there was a presence of arteries and nerve fascicles. The arteries were of varying dimensions, some being very large. The nerve fascicles were distinguished in sections processed for the pan-neural marker protein gene-product 9.5 (PGP 9.5). Some of the arteries were supplied by an extensive perivascular innervation, as seen via PGP 9.5 staining. As seen via processing for the rate limiting enzyme in catecholamine synthesis, tyrosine hydroxylase (TH), sympathetic innervation was found to be a constituent of this innervation. There was furthermore a marked occurrence of immunoreactions for the α1-adrenoreceptor in arterial walls. Also, there was a presence of immunoreactions for the substance P (SP)-preferred receptor, the neurokinin-1 (NK-1) receptor in arterial walls. This receptor was particularly detected in the endothelial parts. The study shows that the arteries in the target area are accompanied by nerve fascicles and that there is a presence of a perivascular innervation, as well as a presence of adrenergic and NK-1 receptors in arterial walls, in this region. Thus, arteries in this area are under distinct neural control. The nerve-related characteristics of the area targeted in the successful polidicanol injection treatment for Achilles tendinosis are here for the first time shown.

The purpose of the experiments was to investigate how inhalation of 100% oxygen affected cognitive performance. A test battery was developed that was designed to capture different aspects of cognitive processes, i.e., perception, attention, working memory, long-term memory and prospective memory. All tests were verbally based, thus reducing cognitive spatial processes to a minimum. In experiment 1, 48 participants volunteered in a complete factorial within-participant design. Two different conditions for type of gas were used, inhalation of 100% oxygen and inhalation of breathing air (approximately 21% oxygen balanced with nitrogen). The inhalation was performed during the 1 min prior to starting each separate test. The instructions for each test were given during the inhalation period. All participants inhaled oxygen or breathing air through a Swedish military pilot mask. Physiological (heartbeats per minute and blood oxygen saturation level) reactions were recorded continuously throughout the session. Participants also completed a mood-state questionnaire before and after the test battery. The results revealed that cognitive performance were not affected by inhalation. Hence, this experiment does not replicate previous findings that suggest that inhalation of 100% oxygen could increase cognitive performance. Another experiment was performed to control for methodological issues. Experiment 2 revealed exactly the same pattern, i.e., inhalation of oxygen did not affect cognitive functioning.